Encapsulation of ionic electromechanically active polymer actuators

Biomimetic movement and low operating voltage have made ionic electroactive polymer actuators (iEAPs) interesting for applications where interactions with living organisms occur, such as haptic devices operating mainly in air or minimally invasive or chronically implanted medical devices operating in biological fluids. However, not all materials that are typically used in the fabrication of iEAPs are biofriendly, nor are the biological environments with various electrolyte compositions safe or optimal for the actuator. This paper presents a comprehensive overview of materials and methods that have been previously used to encapsulate ionic electroactive polymer actuators. Recently, increasing emphasis has been given to the miniaturization of actuators for the biomedical field, and therefore in the detailed overview we have focused on automated, tunable and industrially applicable coating methods, together with promising biocompatible encapsulant materials. In the final section, we introduce a carbon-based actuator that has been dip-coated with polydimethylsiloxane elastomer that shows extended lifetime during actuation in water.